- It is believed that the Earth is about 4500 million years old and that life began about 3500 years ago.
- There is some debate as to whether the first life developed due to the conditions on Earth, or whether simple life forms arrived from another planet.
- We can date rocks. Fossils are found in rocks, so we can date when different organisms existed.
- Fossils may be formed in various ways:
- from hard parts of…